New YorK AGRICULTURAL EXPERIMENT STATION. 393 
of calcium oxid (lime) is equal to about 1.3 pounds of calcium 
hydroxid (slaked lime) and to about 1.8 pounds of carbonate 
of lime. 
WEIGHT OF A BUSHEL OF LIME. 
It is the custom in some places to sell lime by the bushel. 
It should be sold only by weight, because the weight of a 
bushel varies greatly according to a variety of conditions, 
chief among which are porosity of the limestone burned and 
the conditions of burning. The average weight of a bushel 
(heaped measure) of stone-lime is given as 75 to 93 pounds, 
but it may vary from 60 to 120 pounds. Magnesian stone-lime 
usually runs somewhat lower. Oyster-shell lime varies from 
40 to 75 pounds a bushel and averages about 60. 
WHAT LIME COMPOUNDS DO IN SOILS. 
Lime compounds, when applied to soils, produce certain 
specific effects, which, for convenience, may be considered 
under three heads: (1) Chemical, (2) biological, and 
(3) physical. These will be considered in brief outline. 
CHEMICAL EFFECTS. 
The direct chemical effects of lime compounds in soils may 
be conveniently grouped under two general heads: (1) Ren- 
dering available some insoluble forms of plant-food, especially 
in case of certain compounds containing potassium or phos- 
phorus; and (2) neutralizing excessive acidity of soils. Lime 
in the forms of quicklime, slaked lime and carbonate has the 
power to neutralize acids but sulphate of lime (land-plaster) 
has not. The rapidity with which soil acidity is neutralized 
depends primarily upon (a) the fineness of the lime compound 
and (b) the thoroughness with which it is distributed through 
the soil. 
BIOLOGICAL EFFECTS. 
The lime compeunds previously mentioned tend to make 
conditions favorable for the action of certain important micro- 
